Weak and strong stabilization of linear systems

We study the problem of stabilizing a distributed linear system on a subregion of its geometrical domain. We are concerned with two methods： the first approach enables us to characterize a stabilizing control via the steady state Riccati equation, and the second one is based on decomposing the state space into two suitable subspaces and studying the projections of the initial system onto such subspaces. The obtained results are performed through various examples.     

The relation between electric auditory brain stem and cognitive responses and speech perception in cochlear implant users

Electrically evoked brainstem responses (EABR) and event-related cortical potentials were recorded in seven postlingually deaf adults who were experienced users of a Nucleus multichannel cochlear implant. The patients were divided into two subgroups: good performers and moderate performers. Poor EABR were found in two of the moderate performers. The latencies and amplitudes of the cortical N1 P2 complex in the good performers were within the same range as those of subjects with normal hearing, but were deviant in the group of moderate performers. This may indicate disturbed cochleotopical organization of the auditory cortex in the latter group. P300 measurements in the good performers showed normal latencies, whereas in the moderate performers they were prolonged. The results suggest that the outcomes of electrophysiological measurements to assess the integrity of a patient's auditory neural system on a brainstem and a cortical level, are related to the patient's performance with the cochlear implant.     

Energy efficient teaching-learning-based optimization for the discrete routing problem in wireless sensor networks

Wireless sensor networks (WSNs) are composed of sensor nodes, having limited energy resources and low processing capability. Accordingly, major challenges are involved in WSNs Routing. Thus, in many use cases, routing is considered as an NP-hard optimization problem. Many routing protocols are based on metaheuristics, such as Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO). Despite the fact that metaheuristics have provided elegant solutions, they still suffer from complexity concerns and difficulty of parameter tuning. In this paper, we propose a new routing approach based on Teaching Learning Based Optimization (TLBO) which is a recent and robust method, consisting on two essential phases: Teacher and Learner. As TLBO was proposed for continuous optimization problems, this work presents the first use of TLBO for the discrete problem of WSN routing. The approach is well founded theoretically as well as detailed algorithmically. Experimental results show that our approach allows obtaining lower energy consumption which leads to a better WSN lifetime. Our method is also compared to some typical routing methods; PSO approach, advanced ACO approach, Improved Harmony based approach (IHSBEER) and Ad-hoc On-demand Distance Vector (AODV) routing protocol, to illustrate TLBO’s routing efficiency.     

Air-bone gap in patients with X-linked stapes gusher syndrome

It is often possible to elicit the stapedius reflex in patients suffering from recessive X-linked progressive mixed deafness syndrome with stapes gusher. The presence of an air-bone gap in the audiogram and the ability to elicit the stapedius reflex are conflicting. Measurements were performed on two patients who were suffering from this syndrome, to establish whether the hearing loss was of the mixed or purely sensorineural type. It was argued that, owing to congenital malformations, the audiovestibular system might act as a more than normally efficient transducer, to convert skull vibrations into inner ear fluid motions, leading to bone conduction thresholds that are better than expected. The results of tone and speech audiometry, stapedius reflex measurements, and brainstem evoked response audiometry in this study showed a pattern similar to that generally seen in patients with purely sensorineural hearing loss. This supports the hypothesis that the air-bone gap in the audiogram does not have the usual significance of a conductive hearing loss component.     

Implantable hearing devices for sensorineural hearing loss: a review of the audiometric data

BACKGROUND: Child fatality review (CFR) by interagency teams can contribute to the prevention of childhood deaths. We investigated the potential usefulness of Georgia's CFR, legislated in 1990 primarily to prevent death from child maltreatment, for identifying preventable deaths from injury and sudden infant death syndrome (SIDS). METHODS: Using CFR report data and death certificate data, we examined reviewed and nonreviewed childhood deaths in Georgia in 1991 and examined data by etiology, county, risk factors, and preventability. RESULTS: Injury or SIDS caused 33.2% of childhood deaths in Georgia in 1991; CFR reviewed 29.4% of these. Child fatality review was most sensitive for investigating death from intentional injury (40.5%) and SIDS (35.3%). Review teams reassigned the cause of five deaths (2.0%) to child abuse or neglect. County participation was low (31.4%). Overall, 29.0% of deaths were judged preventable. CONCLUSIONS: Georgia's CFR has potential for identifying preventable childhood deaths. Refinements in the system can increase the number and accuracy of death investigations. By participating in the system, physicians may make meaningful contributions to preventing childhood death in their own communities.     

5G enhanced mobile broadband multi-criteria scheduler for dense urban scenario

Telecommunication Systems - Mobile communication networks have entered a new age by introducing fifth-generation technologies (5G). The International Union of Telecommunications (IUT) proposes new...     

Ab initio modelling of localized corrosion: Study of the role of surface steps in the interaction of chlorides with passivated nickel surfaces

Periodic DFT calculations have been performed on a (5 3 3)-oriented hydroxylated NiO surface to model the influence of step edges on the adsorption and sub-surface insertion of Cl at the surface of the passive film on nickel. With increasing Cl coverage, substructures of Ni(OH)₂, Ni(OH)Cl or Ni(Cl)₂ composition are formed and detached from the surface, suggesting a major role of the step edges in the Cl adsorption-induced thinning mechanism of the oxide film. The calculated energies show the promoting effect of the adsorption of Cl on the energy of detachment of the substructures. At surface saturation, sub-surface insertion becomes energetically more favourable than adsorption. The results suggest a possible bifurcation from the Cl adsorption-induced oxide thinning mechanism to the penetration-induced mechanism of passivity breakdown at saturation in adsorbed Cl of the step edges.     

Direct normal irradiation-based approach for determining potential regions for concentrated solar power installations in Morocco

In this study, potential sites for concentrated solar power (CSP) installations in Morocco are investigated based on direct normal irradiation (DNI). The DNI data of four Moroccan sites (Missour, Erfoud, Zagora and Tantan) were collected from different satellite databases (NASA SSE, PV GIS-Helioclim, Climate-SAF PVGIS and Solar Med Atlas). However, it is required to mitigate the risks resulting from uncertainties of satellite-based irradiation data by combining satellite data to ground measurements of at least 1 year. The ground-measured data reported in this work are collected from MHP and MDI meteorological stations installed by IRESEN in collaboration with DLR and ONEE in the framework of the enerMENA project. The Liu and Jordan and the Collares Pereira and Rabl models were also used to determine the monthly and yearly average hourly DNI values. The results of this study suggest that Missour, Erfoud and Zagora represent potential sites for CSP power plants installations, except for Tantan.     

Ab initio study of the interaction of chlorides with defect-free hydroxylated NiO surfaces

DFT periodic calculations have been performed to model the adsorption and sub-surface insertion of Cl atoms at increasing coverage on undefective hydroxylated NiO(1 1 1) terraces characteristic of the surface of the passive film on nickel. The results evidence that structural relaxation, splitting the mixed topmost OH/Cl anionic plane, releases the repulsive interactions induced by Cl adsorption, but the effect decreases with increasing Cl coverage with a loss of ∼1.1 eV in stability at surface saturation. Cl sub-surface insertion in the first inner anionic plane also releases the repulsive interactions in the topmost plane but the effect becomes favourable only at high Cl coverage because of inter-layer mixing after surface reconstruction. At low Cl coverage, an unrelaxed diatomic Ni-OH layer weakly bonded to the oxide and likely to dissolve is formed after sub-surface insertion, suggesting a hybrid mechanism of local oxide thinning. Adsorption of Cl by place exchange is energetically favourable but does not seem to promote dissolution. Insertion into the lattice may promote dissolution but it is energetically favourable only at high Cl surface coverage, which is not a likely situation due to Cl repulsive interaction on the surface. For undefective terraces of the passive film, the reported calculations do not confirm the existing hypotheses of adsorption-induced oxide thinning or chloride sub-surface penetration.